Manufacture of aryl sulphenamides



Fatented July 23,1943

MANUFACTURE PATENT OFF OF ARYL sULPHnNAM'mEs Ralph A. Coleman, N augatuck, Conn, assignor to United States -Rubber Company, New York, N. Y., a corporation of New Jersey No Drawing. Application August 31, 1944, Serial No. 552,197

This invention relates to the manufacture of aryl sulphenamides of the formula aryl-SNH2, where aryl is an aromatic nucleus of the benzene or naphthalene series, which nucleus is further substituted by an electro-negative group.

Examples of such electro-negative groups include halogen (Cl, Br, I), nitro, acyl, carboxyl, sulphonamide ('SO2.N'I-I2 carboxyl amido (CONH2), nitroalkylene (e. g. CH2.NO2), etc. The electro-negative group acts to stabilize the chemical against decomposition.

I have discovered that such aryl sulphenamides can be prepared from reacting, on the corresponding aryl mercaptan (having the said electro-negative attached to aryl), usually in the form of its water-soluble alkali-metal salt, with monochloramine (NI-12.01), in aqueous solution.

This reaction does not work for preparing all aryl sulphenamides, for example, thiophenol or its salt on treatment with monochloramine is oxidized to diphenyl disulfide.

The general formula for the mercaptan to be employed for the purposes of this invention is illustrated by where R is the stabilizing electro-negative group, further examples of which are carbonyl, as in pmercapto acetophenone 1 iii and carboxy ester, as in p-mercapto ethyl benzoate J)C2Hu The reaction may be carried out in water solution by mixing an aqueous solution of monochloramine and an aqueous solution of the mercaptan. It is advisable to keep the temperature below 30 C. and to mix the solution at a moderate 1 Claim. (01. zen-.551)

monochloramine per-mol of mercaptan should be used. Adequate ventilation for monochloramine vapor should be provided.

Whether the monochloramine solution is added to the aryl mercaptide solution or vice versa is immaterial although the former is preferred.

EXAMPLE 1.-0-NII'R0 PHENYL SULPHENAMIDE S-Na NO: NO:

SNHa

+ NaCl Sodium o-nitro phenyl mercaptide A solution of 18.1 g. o-nitro thiophenol in 340 cc. cold water containing 4.6 g. sodium hydroxide is prepared. Any disulphide due to air oxidation of the alkaline solution is removed by filtration.

Monochloramine SNB.

+ NHRCI a short time after its preparation. It is solution B. Ice should be present at all times.

The monochloramine solution B is added rapidly to the sodium o-nitro phenyl mercaptide solution with stirring. A fiocculent yellow solid precipitates which is filtered 01f, washed with water and dried. Yield 7.7 g. o-nitro phenyl rate. At least one stoichiometric proportion of sulphenamide melting -124" 0.

EXAMPLE 2.-P-NITRO PHENYL SULPHENAMJIDE A damp filter cake of sodium p-nitro phenyl mercaptide (24 g.) is dissolved in 225 cc. water.

as described in Example 1.

A solution of monochloramine is prepared EXAMPLE 3.2,5-DICHLORO PHEN'YL'SULPHEN MIDE 2,5-dichloro thiophenol (22.8 g.) is dissolved in a solution of 5.1 g. sodium hydroxide in 110 cc. Water. is removed by filtration, then 25 cc'. water is added to the filtrate.

The monochloramine solution is prepared from Chlorine g.'.' 9.05 Sodium hydroxide g 112 Ice and water cc 128 28% ammonium hydroxide L cc a 16.5 Ice and water cc 159 as described in Example 1.

A small amount of insoluble material The monochloramine solution is added rapidly to the sodium 2,5-dichloro phenyl mercaptide solution. In a short time a white solid precipitates which is filtered off, washed with water and dried. A yield of 22.3 g. of 2,5-dich1oro phenyl sulphenamide melting 62-63 C, is obtained.

I Examples of other sulphenamides which may be similarly prepared are 2,4-dinitro phenyl Asulphenamide, anthraquinone 2-sulphenamide, 2-nitro-4-chlorobenzene sulphenamide, 4-benzoyl benzene sulphenamide, 4-(benzene sulphonyl) benzene sulphenamide, and 4-acetyl benzene sulphenamide.

,Having thus described my invention, what I claim and desire to protect by Letters Patent is: As a new compound 2,5-dich1oro phenyl sulphenamide.

RALPH A. COLEMAN. 

